basal

adj

1. Basic, elementary; relating to, or forming, the base, or point of origin.

   “This is the basal idea.”

   “The organism needs more energy on basal maintenance.”

   “A basal reader is a kind of book that is used to teach reading.”

2. Associated with the base of an organism or structure.

   “In the spring, basal leaves emerge from a stout taproot.”

3. Of a minimal level that is necessary for maintaining the health or life of an organism.

   “a basal diet”

4. In a phylogenetic tree, being a group, or member of a group, which diverged earlier. The earliest clade to branch in a larger clade.

   “Hittite is a basal Indo-European language.”

   “A magnolia is a basal angiosperm.”

noun

1. base, bottom, minimum
2. Any basal structure or part